A cannon or cram cannon Component, that can launch ammo parcels towards ally vehicles and give them more ammo.

the vehicle recieving the ammo must have an ammo port that can gather the ammo.

The reason why this would make for a nice cram Component is mainly because of how crams gain damage over time.
This could be converted into ammo potency over time. Cram materials could be exchanged for ammo materials. ammo materials could work like ammo processors with their 20 ammo per second and each autoloader connected increases this ammo conversion by 15 or something like that. It´s basically like keeping ammo boxes stocked up in your cannons ready to fire, but your vehicle´s own guns can not utilize the ammo unless you shoot yourself.

This would make for an interesting Component in terms of FTD torunaments as tourneys could be entirely based of of having supply vehicles thus making ammo Resources dependent on your total materials budget rather than them being an universal set budget.

It also means you have a key target that needs to be dealt with. either that or you would need to take out the guns that supply the ammo on multiple vehicles.
the ammo could also be volatile much like regular ammo or APS HE Shells.

you could also share ammo through ammo ports but the cannons allow you to share over long distances and offer faster delivery speeds.

In order to account for missing shots the parcel could come in the form of a ball that can roll on the ground(or just slide like ice) and be magnetically docked to nearby ammo ports.

enemy vehicles could also allocate Engine Power to these ports in order to increase pull force as to hopefully steal ammo in case there are any enemy parcels nearby. the ports would of course have a range but now the target could be contested by both thus adding Another risky tradeoff.

so yea, your regular vehicle could have let´s say 2000 ammo and this cannon could have sole ammo boxes that add up to that ammount or more thus making most of your vehicle a big pile of ammo that could go up at any time.
there could also be an armored variant with less on board ammo as to not make the system all to volatile.

Why not just use a drone cannon to launch a resource block a few kilometers?

As the username suggests, I am obsessed with versatility. Lots of missiles and advanced cannons for weapons, prefabs for most functions to be put in 'slots' and the actual big ships and tanks being just blocks made to go slightly under 30 m/s surrounded by hulks made of subvehicles.